Bladder reconstruction using autologous smooth muscle cell sheets grafted on a pre-vascularized capsule.

Construction of functional vascularized three-dimensional tissues has been a longstanding objective in the field of tissue engineering. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate functional vascularized smooth muscle tissue flaps for bladder reconstruction in a rabbit model was tested. Skin tissue expanders were inserted into the groin to induce vascularized capsule pouch formation.

Tissue expander capsule as an induced vascular bed to prefabricate an axial vascularized buccal mucosa-lined flap for tubularized posterior urethral reconstruction: preliminary results in an animal model.

Surgical repair of complex posterior urethral disruptions remains one of the most challenging problems in urology. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate axial vascularized buccal mucosa-lined flaps for tubularized posterior urethral reconstruction in a rabbit model was tested. The experiments were performed in three stages.

Tubularized urethral reconstruction using a prevascularized capsular tissue prelaminated with buccal mucosa graft in a rabbit model.

Tubularized graft urethroplasty fails largely because of inadequate graft take. Prefabrication of buccal mucosa lined flap has theoretical indications for constructing neourethra with an independent blood supply. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate an axial vascularized buccal mucosa-lined flap for tubularized urethral reconstruction in a rabbit model was tested.

Substitution of the precursor peptide prevents anti-prM antibody-mediated antibody-dependent enhancement of dengue virus infection.

Antibody-dependent enhancement (ADE) is currently considered as the mechanism underlying the pathogenesis of severe dengue disease. Many studies have shown that precursor (pr) peptide-specific antibodies do not efficiently neutralize infection but potently promote ADE of dengue virus (DENV) infection. To explore the effect of pr peptide substitution on neutralization and ADE of DENV infection, the rabbit anti-prM polyclonal antibodies (pAbs) and anti-JEVpr/DENV-M pAbs were prepared, and the neutralization and ADE of these two pAbs were further compared.

Association of the ADIPOQ Rs2241766 and Rs266729 Polymorphisms with Metabolic Syndrome in the Chinese Population: A Meta-analysis.

Objective: This meta-analysis was performed to summarize the association of the ADIPOQ rs2241766 and rs266729 polymorphisms with metabolic syndrome (MS) in the Chinese population.

Methods: We searched for articles in MEDLINE via PubMed, EMBASE, HuGE Navigator, CNKI, and Wanfang databases and calculated odds ratios (ORs) with 95% confidence intervals (CIs) to determine the strength of associations in fixed- or random-effects models.

Results: We included 21 articles in the meta-analysis: 17 reports of ADIPOQ rs2241766 with 3628 cases and 3000 controls and 8 of rs266729 with 2021 cases and 2226 controls.

Structural stability of E. coli trigger factor studied by synchrotron small-angle X-ray scattering.

Solution small-angle X-ray scattering (SAXS) is an effective technique for quantitatively measuring the compactness and shape of proteins. We use SAXS to study the structural characteristics and unfolding transitions induced by urea for full length Escherichia coli trigger factor (TF) and a series of truncation mutants, obtaining and comparing the radiuses of gyration (Rg), the distance-distribution function (P(r) function) and integrated intensity of TF variants in native and unfolding states. The C-terminal 72-residue truncated mutant TF360 exhibited dramatic structural differences and reduced stability compared with the whole TF molecule, while the N-domain truncated mutant MC maintained its compact structure with reduced stability.

The association between androgen receptor gene CAG polymorphism and polycystic ovary syndrome: a case-control study and meta-analysis.

Purpose: Many studies have been carried out to confirm the relationship between androgen receptor gene CAG repeat polymorphism and polycystic ovary syndrome (PCOS), without consistent results. Hence we conducted the current study to research this relationship.

Methods: 224 Chinese Han women with PCOS and 223 in vitro fertilization and embryo transplantation (IVF-ET) infertile women with tubal factor or male infertility served as the controls were recruited in our study.

C-terminal 13-residue truncation induces compact trigger factor conformation and severely impairs its dimerization ability.

Trigger factor (TF) is the first chaperone to interact with nascent chains and facilitate their folding within bacteria. TF possesses a three-state equilibrium in vivo: monomeric TF bound to ribosome, free monomeric, and dimeric TF in cytoplasm. TF consists of an N-terminal ribosome binding domain, a middle peptidyl-prolyl cis/trans isomerase (PPIase) domain and a C-terminal domain involved in substrate binding and dimerization.

Braided thin-walled biodegradable ureteral stent: preliminary evaluation in a canine model.

Objectives: To evaluate a novel designed degradable ureteral stent.

Methods: A total of 24 male Beagles, each with bilateral stents implanted (a biodegradable ureteral 4.5-Fr stent and a standard 4-Fr biostable stent) were divided into four groups.

Identification of a novel infection-enhancing epitope on dengue prM using a dengue cross-reacting monoclonal antibody.

Background: Dengue virus (DENV) infection is the most important arthropod- borne viral disease in human, but antiviral therapy and approved vaccines remain unavailable due to antibody-dependent enhancement (ADE) phenomenon. Many studies showed that pre-membrane (prM)-specific antibodies do not efficiently neutralize DENV infection but potently promote ADE infection. However, most of the binding epitopes of these antibodies remain unknown.

Induction of virus-neutralizing antibodies and T cell responses by dengue virus type 1 virus-like particles prepared from Pichia pastoris.

Background: Dengue is currently a significant global health problem but no vaccines are available against the four dengue serotypes virus infections. The development of safe and effective vaccines has been hampered by the requirement of conferring complete protection against all four dengue serotypes and the lack of a convenient animal model. Virus-like particles (VLPs) have emerged as a promising subunit vaccine candidate.

[Cardio-myogenic differentiation of human amniotic fluid colony derived stem cells in the form of embryonic body-like structure].

Objective: To investigate cardio-myogenic differentiation potential of human amniotic fluid colony derived stem cells (HAFCDSC) in the form of embryonic body (EB)-like structure in vitro.

Methods: HAFCDSC were isolated from second trimester amniotic fluid which was backup of amniocentesis specimens. The forth passage of HAFCDSC were cultured by hanging-drop preparation in complete medium for 5 days to form EB-like structures followed by inducing medium in regular tissue culture dishes for 2 weeks (experiment group).

Tissue engineering of bladder using vascular endothelial growth factor gene-modified endothelial progenitor cells.

Purpose: This study assessed the use of vascular endothelial growth factor (VEGF) gene-modified endothelial progenitor cells (EPCs) seeded onto bladder acellular matrix grafts (BAMGs), to enhance the blood supply in tissue-engineered bladders in a porcine model.

Methods: Autologous porcine peripheral EPCs were isolated, cultured, expanded, characterized, and modified with the VEGF gene using an adenovirus vector. The expression of VEGF was examined using reverse transcriptase polymerase chain reaction (RT-PCR) and an enzyme-linked immunosorbent assay (ELISA).

A method for generating precise gene deletions and insertions in Escherichia coli.

A simple and general method for disrupting chromosomal genes and introducing insertions is described. This procedure involves eliminating wild-type bacterial genes and introducing mutant alleles or other insertions at the original locus of the wild-type gene. To demonstrate the utility of this approach, the tig gene of Escherichia coli was replaced by homologous recombination with a cassette containing the chloramphenicol resistance gene and the sacB gene.

Selection and identification of B-cell epitope on NS1 protein of dengue virus type 2.

NS1 of dengue virus (DENV) is an important non-structural protein, which plays an important role in DENV replication and dengue infection. In this study, using the phage-displayed peptide library screening method and purified anti-DENV2-NS1 polyclonal antibody immunoglobulin G (IgG) as target, which was generated from the purified recombinant expressed DENV2-NS1 protein immunization on rabbit, seven B-cell epitopes of DENV2-NS1 protein were screened. Considering the results of comprehensive bioinformatic analysis on NS1 B-cell epitopes, possible dominant B-cell epitopes are located in amino acids residues 36-45, 80-89, 103-112, 121-130, 187-196, 295-304, and 315-324 of the NS1, and two epitope-based NS1 protein dodecapeptides corresponding to the predominant epitopes (PA10: (36)PESPSKLASA(45) and AA10: (187)AIKDNRAVHA(196)) were chosen for synthesis.

PPIase domain of trigger factor acts as auxiliary chaperone site to assist the folding of protein substrates bound to the crevice of trigger factor.

Trigger factor (TF) is the first chaperone encountered by nascent chains in bacteria, which consists of two modules: peptidyl-prolyl-cis/trans-isomerase (PPIase) domain and a crevice built by both N- and C-terminal domains. While the crevice is suggested to provide a protective space over the peptide exit site of ribosome for nascent polypeptides to fold, it remains unclear whether PPIase domain is directly involved in assisting protein folding. Here, we introduced structural change into different regions of TF, and investigated their influence on the chaperone function of TF in assisting the folding of various substrate proteins, including oligomeric glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and monomeric carbonic anhydrase II (CA II) and lysozyme.

Infection and replication of avian influenza H5N1 virus in an infected human.

The highly pathogenic avian influenza H5N1 viruses usually cause severe diseases and high mortality in infected humans. However, the tissue tropism and underlying pathogenesis of H5N1 virus infection in humans have not been clearly elucidated yet. In this study, an autopsy was conducted to better understand H5N1 virus distributions in tissues of infected humans, and whether H5N1 virus can replicate in extrapulmonary tissues.

Structural rearrangements and the unfolding mechanism of a Trigger Factor mutant studied by multiple structural probes.

Trigger Factor (TF) is a three-domain chaperone which catalyzes nascent peptide folding and harbors peptidyl-prolyl cis-trans isomerase activity. The multi-domain structure of TF makes it an interesting and challenging candidate for studies of the structural properties and functional behavior of individual domains or combined domain constructs. Here we constructed a TF mutant, NC, combining the N- and C-domains that are responsible for TF's chaperone function, and compared structural changes and unfolding characteristics of NC with wild-type TF by monitoring fluorescence spectra, far-UV CD, chemical crosslinking, DSC and binding with hydrophobic probes (ANS or bis-ANS).

Alcohol oxidase (AOX1) from Pichia pastoris is a novel inhibitor of prion propagation and a potential ATPase.

Previous results suggest that methylotrophic yeasts may contain factors that modulate prion stability. Alcohol oxidase (AOX), a key enzyme in methanol metabolism, is an abundant protein that is specific to methylotrophic yeasts. We examined the effect of Pichia pastoris AOX1 on prion phenotypes in Saccharomyces cerevisiae.

"Restoration" of glutathione transferase activity by single-site mutation of the yeast prion protein Ure2.

The yeast prion Ure2p is composed of an N-terminal prion domain, and a C-terminal globular domain, which shows similarity to glutathione transferases (GSTs) in both sequence and structure. Ure2p protects Saccharomyces cerevisiae cells from heavy metal ion and oxidant toxicity. Ure2p shows glutathione-dependent peroxidase (GPx) activity, which is often an adjunct activity of GSTs, but wild-type Ure2p shows no detectable GST activity toward the standard substrate 1-chloro-2,4-dinitrobenzene (CDNB).

Quality of embryonic bodies and seeding density effects on neural differentiation of mouse embryonic stem cells.

Mouse embryonic stem (ES) cells can be differentiated into neural lineage cells, but the differentiation efficiency remains low. This study revealed two important factors that influence the neural differentiation efficiency of mouse ES cells: the first is the quality of embryonic bodies (EBs); good quality of EBs consistently originated from a suspension culture of 1x10(5) ES cells/ml serum-free chemically defined neural inducing medium and they exhibited a smooth round shape, with a dark central region surrounded by a light band. Such EBs are capable of attaining high neural differentiation efficiency.

Thermal unfolding of Escherichia coli trigger factor studied by ultra-sensitive differential scanning calorimetry.

Temperature-induced unfolding of Escherichia coli trigger factor (TF) and its domain truncation mutants, NM and MC, were studied by ultra-sensitive differential scanning calorimetry (UC-DSC). Detailed thermodynamic analysis showed that thermal induced unfolding of TF and MC involves population of dimeric intermediates. In contrast, the thermal unfolding of the NM mutant involves population of only monomeric states.

Trigger factor assisted folding of green fluorescent protein.

Guanidine induced equilibrium and kinetic folding of a variant of green fluorescent protein (F99S/M153T/V163A, GFPuv) was studied. Using manual mixing and stopped-flow techniques, we combined different probes, including tryptophan fluorescence, chromophore fluorescence and reactivity with DTNB, to trace the spontaneous and TF-assisted folding of guanidine denatured GFPuv. We found that both unfolding and refolding of GFPuv occurred in a stepwise manner and a stable intermediate was populated under equilibrium conditions.